Tips for Creating Poster-Sized Prints

Today our Guest Expert, Tyler Goering talks about the ins and outs of printing poster-sized prints. Tyler is Director of Business Development at Inkfarm.com

Tips for Creating Poster-Sized Prints

Making your own posters can be a fun and creative way to decorate your home or to promote your projects. These can often be made from photographs or strictly from a graphics editing program. Making these large prints can be a little complicated and there are a few things you should look out for before you decide to spend the money on a large batch of prints.

Digital images in general can be kind of tricky to print out. Sometimes you will print them out and what looked great on the screen comes out blurry on paper or is much smaller than you thought it would be. This is because digital images are usually measured in pixels and pixels are a relative measurement. The physical size of a pixel changes based on the specific monitor and its resolution. With these two factors it is nearly impossible to accurately measure how big your picture will be without looking distorted. You need an additional measurement to accurately predict how big a picture you can print.

The measurement you need is PPI (Pixels Per Inch, sometimes marked as DPI or Dots Per Inch). This measurement, as the name implies, is a way to standardize how big a digital image is (pixels) and translate it into a print size (inches). As you can imagine, you could have a very large image with a very small pixel count. If the image has a low PPI (>150), it will look blurry and pixelated when printed. The standard for images on the web is only 72ppi which is why most images you get from the web are of too low a quality to print clearly.

Most large scale printers require at least 150ppi but many recommend up to 200 or even 300. For a large image this is a lot of pixels. For example, if you wanted a 36” x 24” poster at 300 ppi, you would need an image that is 10,800 x 7,200 pixels. For a camera to take an image this big it would have to have 77.7 megapixels (for reference, Nikon’s $8000 D3X camera only has 24.5 megapixels). Even if you took this same poster size and had a 150ppi instead, you would need a 19.4 megapixel camera. For most people this is simply not possible so it is important to plan your posters with reasonable expectations.

Knowing this when you print something will make choosing your print size a lot easier. If you are ok with a lower quality image on your poster, you can weigh the images size vs. quality. To test what the final product will look like, you can go into an image editor such as Photoshop or GIMP and in the Image tab, change the ppi/dpi of the image and print out a small section of it. This will give you a rough idea of what the whole image will look like at various dot densities.

Keep in mind that vector images can be scaled infinitely high. Using vector images can make printing large much easier but these are more for things like typefaces and icons rather than photos. For more information about ppi/dpi and to use our image size calculator, check out my other article here- http://www.inkfarm.com/DPI-and-Image-Size